Excavation devices and methods

ABSTRACT

In one preferred form there is provided an excavation system ( 10 ) for a vehicle ( 12 ). The excavation system ( 10 ) comprises a body ( 14 ) for connection to the vehicle ( 12 ). An excavation device ( 18 ) is provided for being moved by the vehicle ( 12 ) to excavate material from the ground. A steering system ( 24 ) is provided for altering the steering of the excavation device ( 10 ).

FIELD OF THE INVENTION

In preferred forms, the present invention relates to excavation devicesand methods.

BACKGROUND TO THE INVENTION

Trenching is an operation in which earth is excavated to provide atrench. Construction machines that form trenches are typically used inpreparation for laying pipes or conduit.

Chain trenchers and rock wheels are typically used in the industry toform a trench, depending on the application involved. From anOccupational Health and Safety (OHS) standpoint the excavation of atrench is known to be dangerous.

The inventor, among other things, has realised that it would beadvantageous to provide an improved or alternative trencher for specificapplications.

Whilst a background to the invention has been provided, it is to berecognised that any discussion in the present specification is intendedto explain the context of the invention. It is not to be taken as anadmission that the material formed part of the prior art base orrelevant general knowledge in any particular country or region.

SUMMARY OF THE INVENTION

According to a first aspect of preferred embodiments herein describedthere is provided an excavation system comprising a body; and anexcavation device for being moved by a vehicle to excavate material fromthe ground; and a steering system for altering the steering of theexcavation device.

Preferably the body is provided in the form of a keel-type structure.

Preferably the excavation device is inclined to extend towards thevehicle in the direction extending into the ground when the excavationdevice is being moved by the vehicle to excavate material.

Preferably the inclination of the excavation device is backwardlysloping to allow a bottom support bearing housing to clear the base ofthe trench.

Preferably the excavation device comprises an auger. Preferably theexcavation device comprises a rotating cutting auger.

Preferably the keel-type structure shields the conduit, while beinglaid, from excavated earth.

Preferably the keel includes a number of projections that extend alongthe keel to restrain soil from falling into the bottom of the trench.

Preferably the excavation device includes auto pilot system to extendthe cutting device and sweep left and right.

Preferably the steering system includes a mount having a directionaljoint for allowing the excavation device to be directed left or rightwhen being moved by the vehicle.

Preferably the directional joint allows the excavation device to bereadily removed for maintenance and repair.

Preferably the excavation device includes at least one hydraulic pistonarranged either side of the directional joint for steering theexcavation device.

Preferably the steering system is used to counteract a rotation effectof the excavation device.

Preferably the steering system allows for a swing action to be engagedin an automatic continuous swing mode.

Preferably the excavation device includes the steering system includes adeflector for varying the force applied by the ground to the excavationsystem to control the degree to which the excavation device turns.

Preferably the excavation device includes the steering system comprisestwo moveable surfaces arranged either side of the body for usingfriction to control the degree to which the excavation device turns.

Preferably the excavation device includes the excavation system is forthe vehicle and the body is provided for connection to the vehicle.

According to a second aspect of preferred embodiments herein describedthere is provided an excavation system for a vehicle comprising: a bodyfor connection to the vehicle; an excavation device for being moved bythe vehicle to excavate material from the ground; and a steering systemfor altering the steering of the excavation device.

Preferably the steering system includes a mount having a directionaljoint for allowing the excavation device to be directed left or rightwhen being moved by the vehicle.

Preferably the directional joint allows the excavation device to bereadily removed for maintenance and repair.

Preferably the excavation system includes two hydraulic pistons arrangedeither side of the directional joint for steering the excavation device.

Preferably the steering system allows for a swing action to be engagedin an automatic continuous swing mode.

Preferably the steering system provides a deflector for varying theforce applied by the ground to the excavation system to control thedegree to which the excavation device turns.

Preferably the steering system comprises two moveable surfaces arrangedeither side of the body for using friction to control the degree towhich the excavation device turns.

According to another aspect of preferred embodiments herein describedthere is provided an excavation system for a vehicle comprising: a bodyfor connection to the vehicle; an excavation device for being moved bythe vehicle to excavate material from the ground; and a locking systemfor selectively assisting with preventing the excavation device frommoving backwards.

Preferably the excavation system includes an extension mechanism forextending the excavation device when the locking system is engaged toassist with preventing the excavation device from moving backwards.

Preferably the locking system comprises a wedge arrangement for bearingagainst the side walls of a trench formed by the excavation system.

Preferably the wedge arrangement comprises at least one movable abutmentfor bearing against the side walls of a trench formed by the excavationsystem.

Preferably the wedge arrangement comprises two moveable abutmentsarranged either side of the body for bearing against the side walls of atrench formed by the excavation system.

According to another aspect of preferred embodiments herein describedthere is provided an excavation system for a vehicle comprising: a bodyfor connection to the vehicle; an excavation device for being moved bythe vehicle to excavate material from the ground; the excavation devicebeing connected to the body so as to be disposed forwardly of thevehicle when being moved by the vehicle to excavate material.

Preferably the body is configured such that the excavation device isdisposed a substantial distance forwardly of the vehicle.

Preferably the excavation system includes a length laying guidearrangement, the length laying guide arrangement being disposed betweenthe excavation device and the vehicle, when the excavation device isbeing moved by the vehicle to excavate material.

Preferably the length laying guide arrangement includes an inlet guidearrangement and an outlet guide arrangement, the inlet guide arrangementbeing adapted to receive a feed of conduit or cable from above in aposition between the excavation device and the vehicle; and the outletguide arrangement is adapted to provide the conduit or cable in asubstantially horizontally extending position.

Preferably the excavation device is inclined to extend towards thevehicle in the direction extending into the ground when the excavationdevice is being moved by the vehicle to excavate material.

Preferably the excavation device is inclined by between 20 to 30 degreesaway from vertical.

Preferably the excavation device is inclined by less than 25 degreesaway from vertical.

Preferably the excavation device is inclined by less than 20 degreesaway from vertical.

Preferably the excavation device is inclined by about 20 degrees awayfrom vertical.

Preferably the vehicle forms part of the system, the vehicle having aloader arm adapted to lift the body above the ground for transportpurposes and then lower the body into the ground for excavationpurposes.

Preferably the vehicle comprises a high horse power tracked loader.

According to another aspect of preferred embodiments herein describedthere is provided an excavation system having an inwardly projectingexcavation device and a length laying guide arrangement, the excavationdevice being disposed forwardly of a length laying guide arrangement toallow the excavation device to be driven forwardly and for conduit orcable to be laid therebehind.

Preferably the excavation system includes a mount arrangement formounting to a vehicle, the length laying guide arrangement beingdisposed between the excavation device and the mount arrangement.

Preferably excavation device is spaced at least one meter away from themount arrangement, the length laying guide arrangement being adapted toallow relatively stiff material to be laid in a trench.

Preferably the length laying guide arrangement includes a guide adaptedto flex the conduit by about 45 degrees or less.

According to another aspect of preferred embodiments herein describedthere is provided a method for laying lengths in a trench comprising:positioning an excavation device in front of length laying guide and avehicle; driving the excavation device in a forward direction using thevehicle and laying lengths using the length laying guide, the lengthlaying guide being disposed between the excavation device and thevehicle.

Preferably the method includes filling excavated earth behind theexcavation device at the same time as excavating.

Preferably the excavation system includes a vibratory arrangement forproviding high frequency vibration to the excavation device.

Preferably the high frequency vibration is between 5000 to 15000 rpm.

Preferably the high frequency vibration is between 100 to 300 Hz.

Preferably the excavation system includes a vibratory arrangement forproviding low frequency vibration to the excavation device.

Preferably the low frequency vibration is between 300 to 1600 rpm.

Preferably the low frequency vibration is between 10 to 50 Hz.

Preferably the excavation system includes an adjustment facilityallowing the vibratory arrangement to be controlled from within thevehicle.

Preferably the low frequency vibration is aligned to assist withproviding desirable back and forth vibration in the direction of travelof the vehicle and extension of the trench.

Preferably the high frequency vibration is aligned to assist withproviding desirable back and forth vibration in the longitudinaldirection of the auger.

Preferably the excavation system includes an air injection system fordelivering air to the base of the auger.

Preferably the excavation system includes a fluid injection system fordelivering fluid to the base of the auger.

Preferably in a method there is provided at least one of high frequencyvibration or low frequency vibration.

Preferably in a method there is provided at least one of injection orfluid injection. Various combinations may be preferred.

According to another aspect of preferred embodiments herein describedthere is provided an excavation system having an inwardly projectingexcavation device and a keel-type structure, the excavation device beingdisposed forwardly of the keel-type structure to allow the excavationdevice to be driven forwardly and for conduit or cable to be laidtherebehind.

According to another aspect of preferred embodiments herein describedthere is provided an excavation system: comprising an excavation devicefor being moved by a vehicle to excavate material from the ground; and akeel-type structure providing a length laying arrangement for receivinga feed of conduit or cable; the excavation device for extending, intothe ground to remove material to form a trench.

Preferably the excavation device comprises an auger and at least onecutter; the at least one cutter for cutting material from the cuttingface of the trench; the auger providing a spoil moving mechanism forfollowing the at least one cutter to excavate the material cut by the atleast one cutter.

Preferably the keel-type structure includes a plurality of elongateplatform portions that each extend along the body of the keel-typestructure to prevent soil fall into the bottom of the trench.

Preferably the excavation device is supported from below by a bearinghousing and is backwardly sloping in order to allow the bearing housingto readily clear the base of the trench.

Preferably the at least one grinder comprises two counter rotatingmilling elements.

It is to be recognised that other aspects, preferred forms andadvantages of the present invention will be apparent from the presentspecification including the detailed description, drawings and claims.

The present invention is to be construed beneficially to the applicant.

BRIEF DESCRIPTION OF DRAWINGS

In order to facilitate a better understanding of the present invention,several preferred embodiments will now be described with reference toaccompanying FIGS. 1 to 27 wherein:

FIGS. 1 to 9 provide several views of an excavation device 10 accordingto a first preferred embodiment;

FIG. 10 provides a schematic view of a method of operation 82 accordingto a further preferred embodiment of the present invention;

FIGS. 11 and 12 provide further illustrative views;

FIGS. 13 to 17 provide further views illustrating several vibratoryembodiments according to the present invention;

FIGS. 18 to 26 provide several views of an excavation system 148according to a further preferred embodiment; and

FIGS. 27 to 29 provide further illustrative views.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring to FIGS. 1 and 2 there is shown an excavation system 10according to a first preferred embodiment of the present invention. Inone operation the excavation device 10 advantageously allows for pipe tobe laid in a trench. This achieved using a high horse power trackedloader 12 as shown in FIGS. 3 and 4.

As shown in FIG. 1 the excavation system 10 includes a body 14 forconnection to the tracker loader 12. At a first end 16 of the body 14there is provided an excavation device 18 for being moved by the trackedloader 12 to excavate material from the ground.

In the embodiment the body 14 is provided in the form of a keel-typestructure 20 having a second end 22 opposite the first end 16. Moreover,the excavation system 10 includes a steering system 24 for altering thesteering of the excavation device 18.

The steering system 24 includes a mount 26 having a directional joint 28that allows the excavation device 18 to be directed left or right whenbeing moved by the loader 12. The directional joint 28 includes a numberof finger projections 30 each having an opening for receiving a mountingrod 32. Advantageously the directional joint 28 allows the excavationdevice 18 to be removed from the mount 26 for maintenance and repair.

In the embodiment the directional joint 28 separates the body 14 into afirst portion 34 and a second portion 36. The directional joint 28 isangled to limit the weight of the second portion 36 whilst stillallowing the second portion 36 to be sufficiently robust for excavationoperations. The excavation device 18 is provided as part of the secondportion 36. The body of the keel-type structure 20 is provided by thefirst portion 34.

Two hydraulic elements 38, in the form of hydraulic pistons, areprovided as part of the steering system 24. The hydraulic pistons 38 arearranged either side of the directional joint 40 for steering theexcavation device left or right. The hydraulic elements 38 are connectedby a number of pivot mounts 42.

The hydraulic pistons 38 are positioned adjacent the top of the body 14so as to be disposed away from the lower portion of the excavationdevice 18. Notably, a number of surface engagement members 44 areprovided to ensure that the body 14 does not extend an undesirable depthinto the ground. The surface engagement members 44 provide ahorizontally extending abutment 46 for bearing against the ground.

Whilst the described steering system 24 is presently preferred othersystems could possibly use deflection plates. The deflection plates mayprovide at least one moveable surface connected to the keel 20 thatvaries the force applied by the ground to control the degree to whichthe excavation device turns.

In this embodiment the excavation system 10 includes two deflectingplates 48. Notably the deflecting plates 48 are used for steeringpurposes and form part of the steering system 24.

In addition to this the deflector plates 48 provide a locking system 50for selectively assisting with preventing the excavation device 10 frommoving backwards during hard grinding. As such the deflector plates 48both assist with sharper steering and selectively wedge the machine inthe trench to assist grinding.

The locking system 50 in effect provides a wedge arrangement 52 forbearing against the side walls of a trench formed by the excavationsystem 10. The wedge arrangement 52 is hydraulically operated to extendoutwardly such that backward movement causes rear abutment surfaces 54of the wedge 52 to bear into the side wall of the trench. This serves topush in a longitudinal direction (in the direction of the trench) so asto restrain backward movement.

In the manner described the wedge arrangement 52 provides moveableabutments arranged either side of the body 14 for bearing against theside walls of a trench formed by the excavation system 10.

Although not shown in the drawings 1 the system 10 preferably includesan extension mechanism for extending out the excavation device 18 (therotating cutting auger). Various forms of extension mechanism could beemployed for this purpose. With the wedge arrangement 52 securing thebody 14 in position the extension mechanism is able to extend theexcavation device 18 for relatively hard grinding. Notably extensionmechanism is also operable when the wedge arrangement 52 is not engaged.

The body 14 is relatively narrow so as to cut a narrow trench in theground through which the body 14 passes through.

Referring to schematic FIGS. 3 and 4, the keel 20 is mounted to a frame56. The frame 56 forms part of the body 14 and holds the keel 20 inposition. The rear end 58 of the frame 56 includes a mount 60 forconnection to the tracked loader 12. The mount 60 is adapted toselectively accommodate rotation about a forward axis 62. This isachieved with a conventional tilt attachment for the tracked loader 12and allows the system 10 to adjust side angles to allow working slopesand embankments.

The frame 56 has a number of attachment points (not shown) for weightattachment in the case of rocky ground. The attachment points, in harderrock areas, allow weights to be attached as required to limit vibrationand improve cutting. As would be apparent, weights could also beattached to the laying chute (keel) itself.

The keel 20, in addition to guiding the excavation device 18 in theground, provides a length laying guide arrangement 64 for use in layingcable or conduit along the excavated trench. The length laying guidearrangement 64 allows the excavation device 10 to relatively slowlyguide and lay conduit in the trench before filling. With the trackedloader 12 urging the excavation device 10 forwards continuous lengths 66can be readily laid therebehind at a relatively rapid rate.

Notably while a PVC pipe laying embodiment is considered to be feasible,the use of relatively flexible polyethylene pipe (in comparison to PVCpipe) is preferred. With the use of flexible pipe the length layingguide arrangement does not have to provide the same degree of gradualcurvature when bending the pipe as would be the case with, relativelystiff PVC.

The length laying guide arrangement 64 guides the continuous length 66behind the excavation device 18, between the excavation device 18 andthe loader 12. This occurs as the excavation devices moves forwardly.Advantageously the keel 20 houses the continuous length 66 as the lengthis laid so as to shield the length from excavated earth.

The excavation device 18 is advantageously connected to the body 14 soas to be disposed a substantial distance forwardly of the tracked loader12. This allows the guide arrangement 64 to be relatively long and allowfor gradual length flexing of the pipe as shown.

As shown in FIGS. 3 and 4 the length laying guide arrangement 64includes an inlet guide arrangement 68 and an outlet guide arrangement70. Although schematically shown as passages in frame elements, theinlet guide arrangement 68 and the outlet guide arrangement 48 areprovided as guide rollers so as to limit friction and assist withguiding the pipe/conduit.

As shown the inlet guide arrangement 68 is adapted to receive a feed ofconduit from above in a position between the excavation device 18 andthe loader 12. Comparatively, the outlet guide arrangement 70 is adaptedto provide the conduit in a substantially horizontally extendingposition after flexing.

The excavation device 18 is inclined in a direction extending towardsthe vehicle loader 12 in the direction extending into the ground whenthe excavation device is being moved by the vehicle to excavate earth.

Advantageously the loader arm 72 of the loader 12 and the configurationof the excavation system 10, allows the loader 12 to lift the body 14above the ground as shown in FIG. 5. The height 74 of excavation device10 is approximately the height of the loader 12.

When above the ground the excavation system 10 is disposed for transportpurposes along roads and the like. When trenching is required theexcavation system 10 is advantageously gradually lowered into the groundto commence excavation. In this embodiment the excavation 10 cuts itsway down at an angle of 20 to 30 degrees.

As shown in FIG. 6, the depth of excavation is advantageously controlledby the height of the loader arm 72 in combination with a hydraulicallycontrolled depth wheel 76 that supports and guides the body 14 of theexcavation system 10. The depth wheel 76 is able to move up and downrelative to the frame 56 along with the loader arm 72 to control thedepth of excavation.

The depth wheel 76 is of a castor type. The castor mounted depth wheel76 is mounted at the front and the top of the excavation system 10 so asto provide a forward facing ground engaging wheel.

As would be apparent from FIGS. 5 and 6 the system 10 allows a trench tobe started by continually lowering the excavating system 10 into theground. The final result is shown in FIG. 6 in which the system 10 hasin effect been surface launched, requiring no pit, with the systemtrenching its way into the ground. Mole boards (not shown) are used likea snow plow to direct the spoil into the trench. In embodiments moleboards direct spoil to go under the loader or away from the trench toallow the trencher tracks to travel on clean ground as desired, as themachine moves forward. FIG. 8 shows the advantageous disposition of thesupport bearing housing and the base of the trench. As shown theexcavating device 18 cuts below the keel 20.

In the overall system, the tracked loader 12 provides variable speedcontrol and high traction. The tracked loader 12 also provides horsepower for driving the excavation device 18. The inlet guide arrangement68 advantageously provides for a relatively low feed angle. As discussedthe particular configuration allows for the pipe to be gradually laid inthe trench.

Yet further advantages include the speed of deployment and the loaderoperator having advantageous visibility and safer control. Furthermore,a relatively concise and consistent laying depth is provided. Thepipe/cable will be laid relatively straight with relatively less layingfriction for easy hauling. This is achieved by the keel 20 providing ashield as the pipe/cable is laid. In addition, the keel 20 obviates theproblem of cave in prior to laying.

The trench is advantageously filled (to a degree) behind the keel 20,using the keel 20 and mole plates so as to mitigate injury liabilityassociated with cave-ins and collapsed trenches.

In another embodiment a warning tape is laid at a lower depth using asimilar laying roller arrangement with an inlet and outlet at adifferent depth.

As shown in FIGS. 8 and 9 the excavation system 10 further includes acompactor 78 for attachment to the rear of the loader 12. The compactor78 advantageously includes a vibration facility 80 for applyingvibration to the earth filling the trench into which the conduit islaid.

Referring to FIGS. 1 to 9, the excavation system 10 is considered toadvantageously provide an inwardly projecting excavation device 18 and alength laying guide arrangement 64. The excavation device 18 is disposedforwardly of the length laying guide arrangement 64 to allow theexcavation device 18 to be driven forwardly and for conduit to be laidtherebehind. The excavation device 18 is advantageously disposed about2-2.5 m from the vehicle with the length laying guide arrangement 64being adapted to allow the conduit to be laid.

It is envisaged that as the system is further engineered larger andlarger pipe or more inflexible pipe will be able to be laid up to aboutsay 160 mm PVC. In embodiments with PVC conduit a support boom ispreferably utilized. Alternatively a platform for a worker could beprovided for manual stick feeding.

The excavation system 10 is considered to provide a relatively narrowexcavation/work area and to require possibly as little as 20% solidexcavation compared to a bucket excavator.

The overall benefit is considered be relatively rapid continuous pipelayering that works particularly well in high water table areas. Thesystem is considered to be relatively efficient in rock up to 50000 psi.It is envisaged that the system will be relatively efficient in rock upto 80000 psi.

There are considered to be overall operational efficiencies and for thesystem to present an alternative to Horizontal Direction Drilling insome applications that may avail lower cost.

The steering system 24 is considered to be particularly advantageous insituations where the excavating device 18 comprises a single auger.

Notably, with a single auger turning anticlockwise the loader driverwill experience a pulling action of the augers rotation to the right(from the operator's point of view). In addition there will be atendency of the rotating auger to feed or pack spill down the left sideof the keel. These actions serve to pull the loader to the oppositedirection of rotation. In the case of an anticlockwise auger theseactions result in pulling to the right.

The relatively deep straight keel 20 makes steering problematic withoutuse of the steering system 24. The steering system 24 is advantageouslyable to generally steer the system as well as accommodate the presenceof uncompacted spoil under tracks of the machine. Electronic directioncontrol is employed in the embodiment.

Although not presently preferred a hydraulically operated hingeddeflector plate extending all the way down the right side of the layingchute may provide additional and sharper steering correction indiffering ground conditions.

The presently preferred arrangement is a directional hinge allowing theauger assembly to be mounted on a support beam that is hinged onto thelaying chute (guide arrangement 64).

The heavy duty hinge, in the embodiment, allows about 10 degrees ofangular movement left or right. When the auger is turned to either sideit cuts in that direction and the resulting earth face comes intocontact with the now exposed beam side so as to act as the rudder and,advantageously, as an additional deflector plate. This is provided bythe second portion 36 shown in FIGS. 1 and 2. In other embodiments morethan 10 degrees of angular movement could clearly be provided.

This performs two tasks: (i) compensation steering to counteract therotation effect of the auger to keep the machine straight in differingground conditions; and (ii) steering the machine through curvedalignments.

Advantageously when turning corners (or otherwise) the auger swingaction can be engaged into an automatic continuous swing mode such thata wider trench is formed. In addition deflector plates are able to steerthe machine themselves in a much sharper radius due to presence of awider trench. This action may be controlled by a programmed electricalcircuit controlling various solenoids. Advanced electronic control ispreferably provided.

FIG. 10 shows a method of operation 82 according to a further preferredembodiment of the present invention. In the method 82, lengths 84 areadvantageously laid in a trench 86.

At block 88, the method 82 includes positioning an excavation device infront of length laying guide and a vehicle. At block 90 the method 82includes driving the excavation device in a forward direction and layinglengths using the length laying guide. The excavating device and lengthlaying guide are disposed in front of the vehicle.

At block 92 the method 82 includes filling excavated earth behind theexcavation device at the same time as excavating. At block 94 the method82 includes compacting the excavated earth using a vibratory compactorattached to the rear of the vehicle.

More particularly in the method 82 a high speed cutting auger is used toemulsify the soil allowing the laying chute to pass through the groundmoving the smallest amount of soil which extrudes to the surface. Thetractive capability of the loader power plant combined with the designallows the laying chute to penetrate many different ground conditions.

Pipe/cable and warning tape are feed into the laying chute guide systemand are set to the exact depth required. As the laying chute passes bythe resulting spoil is channelled by mole boards to fill the trenchimmediately after the chute has passed leaving windrow on top of theincision aligned ready for compaction.

They system provides a relatively rapid one step line assembly typeinstallation process combining: 1) trenching/plowing; 2) assembling; 3)laying conduit; 4) lay warning tape; 5) laying bedding sand; 6)backfilling spoil; and 7) compacting.

The system is readily used for areas with low to medium congestion ofutilities. The system provides main benefits are high levels ofconstruction productivity, workplace safety and responsibleenvironmental management.

This is all completed within a small operational footprint allowing acondensed worksite. The system does this at production rates normallyonly achieved by larger machinery in large open areas, due to theirsize. They system is particularly efficient and can operate in tightboundary alignment's and tight spaces.

The new generation of high horse power (HP) compact tracked loaders isconsidered to be suitable for use with several envisaged systems. Suchloaders have high variable ground speed control and high traction lowground pressure and are able to produce and transfer a high percentageof hydraulic HP to working implements.

The high HP allows the forward mounted auger cutting mechanism to behydraulically driven (supported in front by a main frame incorporating atrench box laying chute). The advantageous design provides for clearvision, smaller & lighter implement weight, no complex mechanical driveangles and advantageous overall safety.

High low/low variable hydraulics power delivery is considered to allowproduction to be as much as 6 meters per minute (360 m per hour) by acrew of 2-3 men. This can be up to 10 times as fast compared to somesystems. Higher rates such as 11 meters per minute are also consideredto be possible.

The design takes advantage of the front end loader's ability to lift outthe very long laying chute from the ground for transport due its longtravel, the design also provides the ability to trench itself into theground by kicking back the angle further at commencement hence there isno need for a specially excavated a starting or finishing pit.

In an embodiment, the weight is transferred to the cutting face and aclear front end and low feed angle allows for relatively stiff 50 mm PVCpipe to be threaded at a low trajectory. In the embodiment, this mayallow stiffer and cheaper PCV (say at $2/m) to be laid in somesituations, as against, polyethylene say at $3/m. Forward facingoperator clear visibility, safer control and comfort are also providedas discussed.

Because the auger is backward sloping approximately 20 degrees it allowsthe placement of a bottom support bearing housing to clear the base ofthe trench which is cut by the lowest teeth. This bearing housingadvantageously supports a long narrow auger which requires support dueto its inability to be any broader due to the desired confined trenchwidth minimization.

In some embodiments a second or mid bearing housing is placed above theauger flights that take the auger side loads induced by the pushingactions of the loader.

The narrow cutting face of the system allows relatively minimalexcavation. The implement does not need to clear soil to a large windrowwhich in itself is a source trench collapse due to ground pressureapplied by spoil weight. As there are no substantially open trenchesthis mitigates injury liability.

The main frame box/laying chute includes adjustable roller guides whichchannel the pipe or product to the desired laying position. Thisprovides straighter pipe laying with less friction for easy hauling.

In embodiments, concise consistent pipe or cable laying warning tapeplacement is also provided by an adjustable depth control wheel whichalso assists with weight distribution.

Pipe/cable and warning tape is feed into the laying chute guide systemset to the exact depth required. As the laying chute passes by theresulting spoil is channelled by otter mole boards to fill the trenchimmediately once the chute has passed leaving windrow on top of theincision aligned ready for compaction.

The standard model auger having carbide cutting teeth along the entireauger flight outer external surface allows extremely efficient cuttingof the trench face. The auger is capable of the narrowest incision modeland deals with Rock to 5,000 psi.

For rock above 5000 psi a hard rock cutter using having bullet nosedcarbide cutting teeth may be used as the auger, in a first cutting pass.Notably, in soft conditions the auger could be replaced with a vibratorysaw.

In softer wetter conditions the emulsifying effect of the auger on thesoil will break down the structure lowering it viscosity force causingthe spoil to either extrude upward or to the sides of the laying chute.This allows the system to make quickest headway for those conditions.

Drilling fluids such as water, air, bentinite and foaming agents can beinjected via the leg at the rear of the auger to increase production bylowering torque. The system emulsifies the cutting to produce a morepumpable slurry spoil.

The vibratory compaction wheel is preferably designed to reach asubstantial depth by compacting upwards in layers to fully expel anyair/oxygen from the sub strata formation to mitigate any acid sulphateconditions through oxidation.

The system relatively minimizes disturbance and though compaction limitsthe chance of erosion. The system provides a green low carbon foot printmethodology due its lower energy consumption. The effect on sensitivewetland areas is considered to be greatly reduced by a low groundpressure high traction/floatation capability of the loader the system isideal for high water tables where it would normally be impossible tobury a pipe as it would float to the surface.

The operation is also relatively rapid, minimizing stress on wild lifeand minimal spoil means less chance destruction of sensitive habitat.

FIG. 11 illustrates a heavy duty rock version that has no laying chute.A rock auger is mounted as close to tracked loader as possible toprovide weight and limit reaction torque. The system only cuts the rockout ready for either a safe trencher (according to FIGS. 1 to 9) oranother laying method. FIG. 12 illustrates the nature of the rock augerenvisaged.

An automatic swing mode is engaged to cut a relatively wide trench andallow for the passage of material either side of the keel. Deflectionsteering plates are used to guide the keel. An electronic systempreferably controls both the deflection plates and rotation of the augerabout its pivot point.

A repetitive programmed auto pilot system of present actions wouldadvance the trencher via the following repeated actions: A) Move to rockface by tracks; B) Expand deflector boards and lock/wedge/brace intrencher; C) Extend/jack out the rotating cutting auger; D) Sweep left;E) Sweep right; F) Retract the rotating cutting auger; and G) Repeatactions A-F.

In particular applications power could be supplied by an independentpower pack for increased horse power if required. In addition the systemcan be used as an alternative to horizontal drilling in certainapplications.

Notably apart from circular rock saws, the use of rock breakers onexcavators is the most common practice. Due to the configuration and theway the breaker works the trench ends up being large V shapes resultingin 2 or 3 times as much rock having to be excavated at great time andexpense, The spoil ends up as unusable boulders and has to be carted anddumped unlike the ground spoil produced by the auger. In comparison tosuch systems the present embodiments provide significant advantages.

Furthermore, rock saws have an inherent fault in that they can only digas deep as the drive motor which is mounted on the axle. This means thatit takes a 4 m wheel to dig a 1.5 meter hole. As a result, the machineends up being massive and very heavy; ie 45 tons and costing say $1.5 m.

In yet further embodiments twin counter rotating augers could be usedfor larger trenches. Various mechanical spoil moving mechanism could beused other than otter boards such as augers and flicking paddles.

The excavation system is considered to provide a trenching/plowinghybrid system providing relatively continuous pipe and cable laying forgreenfield areas. The system is considered to be relatively safe, fastand environmentally friendly. In a number of circumstances theexcavation system 10 is considered to provide a better quality finishedasset.

Referring to FIG. 13, in order to assist the cutting action oneembodiment includes a vibratory arrangement 96. The vibratoryarrangement 96 assists with the overall cutting action. As a whole thesystem is considered to provide: (i) rotational cutting; (ii) augertransportation of spoil; (iii) forward motion of the prime mover; and(iv) sweeping action of the rudder milling head assembly.

Five energy methodologies that may suit the system comprise: (i) highfrequency or sonic assist vertical motion; (ii) low frequency vibrationassist vertical motion; (iii) air assist; (iv) fluid assist; (v) hammeror impact assist horizontal forward motion. Such methodologies areconsidered to provide liquefaction and impact assistance. A combinationof such methodologies may be applied.

The embodiment of FIG. 13 includes a high frequency vibrator 98 that isprovided in the form of a vibratory actuator 100 connected to the augerdrive assembly in which the auger is mounted.

In the embodiment, the actuator 100 has an even number of counterrotating opposing weights. The weights form a group of synchronised offset weights that are driven at high speed. Hydraulic motors provide thevibratory effect when running at about 1200 to 30,000RPM+. The highfrequency vibrator 98 extends and retracts the whole assembly at avibration frequency of between 100 to 300 Hz.

The effect is considered to provide an advantageous fluidisation ofporous materials in combination with the laws of inertia. The wholeauger vibrates relatively quickly. This is considered to make thematerial around and in front of the auger lose friction and to assistwith: (i) cutting—on the cutting edge it aids penetration as it meltsinto the face of the excavation; and (ii) transport on the auger flightsmaking the material flow more like liquid.

This intense vibration is considered to cause a very thin layer ofparticles directly surrounding the auger to lose structure. Instead ofthe stiff mass that requires torque and weight to penetrate, the soilbehaves more like a fluid powder. Fluidisation or liquefaction isconsidered to reduce the friction between the auger and the surroundingformation. This is considered to allow relatively rapid penetration ofthe auger reducing the energy required for forward motion and augerdrive. A more efficient cutting action is considered to be provided.

In addition the high frequency vibration of between 100-300 Hz isconsidered to prevent the formation from sticking to the flights of theauger.

The high frequency vibrator 98 includes a vibration adjustment facilityaccessible by the driver (operator) of the system from within thevehicle. The operator is able to vary the frequency to match thematerial in which the trench is provided, to allow adjustment to providean advantageous penetration rate. Smaller machines can also be builtthan might otherwise have been the case.

In various vibratory arrangements, simultaneous dual frequencyvibrations may be able to be induced (high and low) by different mountpositions of the actuator 98. A mounting position of the actuatordirectly on the auger assembly 106, or on frame of the device ispreferred.

Referring to FIG. 14, embodiments advantageously provide the ability toalter the positioning of the vibratory actuator 100. The rotationalposition of the vibratory actuator is able to be moved over an angularrange 108. In position 110 the primary direction of vibration is alongthe axis 112 which is substantially perpendicular to the cutting face ofthe trench and auger 114

By the varying the placement of any such attachment on the implement thevibration or impact can be controlled i.e. the oscillating device slewsthrough degrees of orientation being moved in position by a hydraulicram so as to pivot and direct its energy in a preferred direction updown or sideways. Various arrangements are possible.

One schematic arrangement shown in FIGS. 15 and 16 uses a hydraulic ram116. The hydraulic ram 116 is able to rotate the high frequency vibrator118. In position 120 the primary direction 122 of vibration issubstantially perpendicular to the ground. In position 124 the primarydirection 122 is substantially in the direction of the ground andtravel. This provides provided action both along and across the auger126

The frequency of the vibration is adjustable. In this embodiment thevibration is hydraulically powered. The frequency is adjustable bycontrolling hydraulic flow to best suit ground conditions.

Referring to FIGS. 17 a and 17 b, the coupling of the vibrator 118provides a degree of free travel in the connection 130 between thevibrator 118 and the auger 132. In the arrangement a degree of slop orspace 136 is provided at the joint 134 that allows for steering. Thespace 136 is provided between the finger portions 138 that receive therod 140 extending along the joint. The wave length of the travel strokeis encouraged by free play in the design.

The connection 132 can be considered as a steering assembly hinge 142.In the case of high frequency the slack in the steering assembly hingemay provide say 0-15 mm travel. The applicant is yet to determinewhether such travel should be increased or decreased. Returning to FIGS.13 and 14, a low frequency vibrator 102 forms part of the vibratoryarrangement 96. Comparatively the rotation cycle is in hundreds ofcycles per minute not thousands. In this embodiment the low frequencyvibrator 102 vibrates at about 100 to 300 rpm. Various low frequenciesare possible.

Notably the lower frequency vibrator 102 provides primary movement inthe direction 144. The low frequency vibrator 102 bounces on a wheel 146that contacts the ground. This may provide say 0 to 35 mm travel betweenthe machine and the front tyre due length of leverage and the lowpressure of the tyre to enable bouncing to act and a non-rigid pivot. Assuch the tyre acts as a spring compressing and decompressing with theaction of the low frequency vibrator 102 (provided be the inertia of theroto-motion of the driver counter weights).

In the low frequency vibrator 102, the offset weights are of a muchheavier build, which produces a longer slow, and strong stroke. Such astroke also advantageously physically forces the cutting teeth into theformation which is considered to be relatively advantageous in hardground conditions and rock. The action is considered to produce aripping and shearing action producing a particle size conducive to anadvantageous flow rate. This is measured by the operator noting theforward travel speed as he varies and adjusting to suit localconditions. The lower frequency vibrator 102 includes a vibrationadjustment facility accessible by the driver (operator) from within thevehicle.

The low frequency vibrator 96 is positioned to provide relativelyvertical vibration. The high frequency vibrator 98 is mounted so thatits action is directed to the auger drive rod as much as is feasiblesuch as by mounting to the casing. The vibration action is substantiallyperpendicular to the longitudinal axis of the auger. The lower frequencyvibrator 102 is fixed on the frame spaced away from the suspended airbag tyre 104 as shown in FIG. 13.

It is considered that conventional rock wheels or chain trenchers arenot as advantageously adapted to the inclusion of such a vibratoryarrangement 96 due to their physical mass in the case of the rockwheeland associated design restrictions such the chains slop and isolation ofthe action by its no ridged linkage.

In another embodiment an air injection system is provided. The airinjection system delivers air at the bottom of the trench at the base ofthe auger assembly. A delivery rate of about 80 to 120 cubic feet perminute is preferred in the embodiment. Air fluidization is a processsimilar to liquefaction whereby a granular material is converted from astatic solid-like state to a dynamic fluid-like state. This processoccurs when a fluid (liquid or gas) is passed up through the granularmaterial.

As detailed on Wikipedia:

-   -   ‘When a gas flow is introduced through the bottom of a bed of        solid particles, it will move upwards through the bed via the        empty spaces between the particles. At low gas velocities,        aerodynamic drag on each particle is also low, and thus the bed        remains in a fixed state. Increasing the velocity, the        aerodynamic drag forces will begin to counteract the        gravitational forces, causing the bed to expand in volume as the        particles move away from each other. Further increasing the        velocity, it will reach a critical value at which the upward        drag forces will exactly equal the downward gravitational        forces, causing the particles to become suspended within the        fluid. At this critical value, the bed is said to be fluidized        and will exhibit fluidic behaviour. By further increasing gas        velocity, the bulk density of the bed will continue to decrease,        and its fluidization becomes more violent, until the particles        no longer form a bed and are “conveyed” upwards by the gas flow.    -   When fluidized, a bed of solid particles will behave as a fluid,        like a liquid or gas. Like water in a bucket: the bed will        conform to the volume of the chamber, its surface remaining        perpendicular to gravity; objects with a lower density than the        bed density will float on its surface, bobbing up and down if        pushed downwards, while objects with a higher density sink to        the bottom of the bed. The fluidic behaviour allows the        particles to be transported like a fluid, channelled through        pipes, not requiring mechanical transport (e.g. conveyor belt).’

In other embodiments a fluid assist unit may find application. As withdown hole drilling a range of different liquids can be introduced toenhance efficient production detergents for stick clays, slipperypolymers to enhance cutting water to dampen dusts cool the cutters down.

In another embodiment an impact hammer is provided. In the embodimentthe impact hammer provides a knocking hammer action attached in much thesame way as the vibrator placed on the auger assembly. The impact hammercould act in a horizontal or North-South latitude rather that up anddown action.

Other action impact may be provided, as in horizontal hammering by thefitting of a percussive hammer similar in action to a rock breaker orimpact ripper. This method may vary from the vibratory actions of highand low frequency in that it travel is action is horizontal and or itmay or may not take the form of an impact. Various orientations arepossible.

In another embodiment continuous laying is provided. For example asubstance could be pumped into the laying chute so as to extrude acontinuous foundation or barrier. Concrete or another substance may besuitable.

In order to assist with maximizing the efficiencies of the system, inthe many differing ground conditions and differing applications,different embodiments will be produced in various models and capacitiesand may be as multi-purpose as a possible buy configuration of thesystem allows. A variable build size matched to the primemover suited toapplication depth width and ground type is envisaged.

Embodiments may have different milling heads including the followingcutting milling auger configurations to suit ground conditions (refersto current model only): (i) 70 mm Rod/Dual fight/low pitch/Bulletcutters; (ii) 70 mm Rod/Single flight high pitch Shark teeth; (iii) 70mm Rod/Dual fight loe pitch Shark Tether; (iv) 125 mm/Barrel reamer/lowpitch/Air assist; (iv) 125 mm/Barrel reamer/high pitch/pizza cutters.

Various methods embodying the invention may provide for high frequencyvibration, low frequency vibration, air assist and fluid assist.Preferred systems preferably provide an automated programmable repeatedaction for hard rock milling through by wedging and hydrolic pressure toprovide high psi purchase leverage capability.

In one embodiment, when the machine is in the trench in hard groundconditions, the mechanism provides: 1) the mechanism hydraulicallyextends to the sides of the trench to wedged to hold the machine formbeing pushed backwards; 2) the front cutting head hydraulically extendsforward will cutting approx. 300 mm; 3) The head then swing side to sidecutting to desired width and then retracts; 4) The wedges them releaseand retract; 5) The machine tracks forward 300 mm. The cycle is thenrepeated.

An excavation system 148 according to another preferred embodiment isillustrated in FIGS. 18 to 25. The system 148 includes a vehicle 150 inthe form of a tractor 152. The tractor 152 pulls an excavationarrangement 154. The excavation arrangement 154 is moveable to and froma raised condition 156 that is suitable for transport to a trenchinglocation.

The excavation arrangement 154 includes an excavation device 158 and akeel-type structure 162. The excavation device 158 is provided in theform of an auger 160. The excavation arrangement 154 is provided to bedriven forwardly to provide a trench. Referring to FIG. 20, as with theprevious embodiment, the excavation device 158 is backwardly sloping,relative to the intended direction of trenching, allowing the excavationdevice 158 to cut below the level 161 of the position 163 from which theexcavation device 158 is supported from below.

FIGS. 21 and 22 illustrate how the excavation device 158 commencesexcavation into the ground 190. The excavation device is backwardlysloping at about 20 degrees and initially contacts the ground 190 suchthat the ground is cut in advance to allow passage of the bottom supportbearing housing.

In a number of embodiments, the angle of repose of the auger is 20degrees or more. This allows the cutters at the base of the auger to cutbelow the depth of the base bearing housing and support providing aclear path for the bearing and support to travel. The base bearinghousing and support are up and under the auger. The angle of inclinationmay be selected to suit the cutting conditions.

FIG. 22 illustrates the providing of a number of projections 192 forsoil restraint. The projections 192 extend along the body of thekeel-type structure 162. The projections 192 are provided to restrainsoil fall into the bottom of the trench. Each projection provides anelongate platform 194 upon which soil is able to fall rather thanfalling into the trench. The projections 192 extend a substantialportion along the length of the keel (from one end to the other). Theprojections 192 are provided as 25 mm fins to assist with stopping soilfalling into the trench.

Returning to FIG. 18, the excavation device 158 is mounted on a forwardend 164 of the excavation arrangement 154. As with the earlierembodiments, the excavation device 158 extends rearwardly away fromvertical in a downward direction as shown (away from the tractor). Inthis sense the excavation device in inwardly projecting, relative to thebody of the excavation arrangement 154.

The excavation device 158 is provided for being moved by the vehicle 150to excavate material form the ground to provide a trench. The keel-typestructure 162 provides a length laying arrangement for receiving a feedof conduit or cable. In a trenching condition the excavation device 158extends a longitudinally into the ground to define a trench depth.

As shown there is provided a frame 166 having a structure 167 and acarriage 168. The carriage 168 includes four wheels. The carriage 168 isconnected to the structure 167 by a connection 170. The connection 170comprises a member having a first pivot 172 and a second pivot 174.

In embodiments an arrangement comprising a locking portion and anabutment is provided to secure the first pivot 172 to provide the raisedcondition 156 and a deployed condition 180 for providing a trench.

A steering system 182 is provided in the form of a rudder 184 at arearward end of the excavation assembly 154. The rudder 184 extends theheight of the keel-type structure 162.

The first pivot 172 allows 90 degrees of movement between securedconditions. From the raised condition 156 to the deployed condition 180the carriage 168 flattens and moves toward the tractor 152 as shown. Thecarriage includes a recess 186 for receiving the structure 1676 which isprovided as a beam. The recess 186 moves from a vertically inclinedcondition facing forwardly to a horizontally inclined condition facingupwardly, as the excavation assembly 154 moves from the raised condition156 to the deployed condition 180. The recess 186 is sized to receivethe beam.

In another embodiment shown in FIG. 27, the auger 160 is provided behindtwo cutters 188. The cutters 188 are provided a double mill havingcounter rotating heads. In use cutters 188 cut material from the cuttingface of the trench. The auger 160 provides a spoil moving mechanism andfollows the cutters 188 to excavate material from the trench.

FIGS. 28 and 29 show possible double cutter and double augerarrangements. Multiple numbers of augers and cutters may be provided inembodiments.

In the context of several embodiments, present optic fibre ploughingthrough hard solid ground even with heavy dozers can take many passes toget a desired depth of say 1200 mm. This is because the ground generallygets harder the deeper one goes. Often the dozer must have heavy massi.e. 60 tons+traction+ and large horsepower. Such dozers are expensiveto own and operate and need special permits and heavy haul equipment tomove. Ripping or pre-ripping expends energy directly against the earth.

In the embodiments the earth is loosened at the point of contact by amilling action to cut and relieve the solid formation. This isconsidered to be able to be done using cheaper lower horse poweragricultural tractors that have PTO power take off to produce therotational action.

Normally agricultural HP is used on very wide large implements to coverthousands of acres at shallow depth. Here there is a concentration allthat power is provide on say a 250 mm wide slot 1200 mm deep. A steeringkeel is used in various embodiments. Heavy weighting is used on rear tohold down the cutters as required.

Double barrel augers or milling heads (2 or More) may be used. Eitherintermeshing as shredders or segregated by gap of desired crushing'ssizes rotating as opposite pairs clockwise feeding spoil in throughcentre or counter clockwise out to the side of the cut trench.Counteracting lengths should have little effect on steering as far aspulling machine off line as they counter balance each other. Thedesigned configuration purpose of these cutters may be to act as millingheads as primary purpose and therefore could be mounted in a trianglewith a 3rd auger purely for lifting spoil out after the front 2 augerscut and grade the spoil and passed it backwards.

The system is considered to be particularly good for floating rock i.e.were a solid formation of baked clay has solid boulders within theformation as they process the boulder as the move forward. This is aproblem for chain and saw trenchers as they could try to lift the wholeboulder though the solid-earth causing high impact and damage as thebolder bounces in elongating hole with each impact.

In one preferred method, according to an embodiment, there is providedprovide power assisted ploughing using a milling auger mounted onsteering rudder to cut and transport the spoil to the surface relievinga narrow channel and clearing the path for a laying keel reducing energyrequired to open the formation.

The method is considered to advantageously distribute energy in arelatively effective way allow say a prime mover to be smaller andlighter in comparison to a number of existing systems that need to exertas much 200 tons of drawbar force to break hard ground.

The method advantageously allows the design of efficient machines,having configurations matching a variety of ground conditions from rockcondition to below the water table. In various forms high and lowfrequency vibration liquid and air injection are mounted on variousprime movers.

In embodiments there is considered to be applications to subsea oceanfloor pipe and cable laying with the use of remotely operated vehicles.Application may also be found in: continuous laying deep concretefoundation diaphragm piling walls; agricultural drainage PTO drivetrailed devices; self-propelled excavator mounted larger diameterinstallations; and other applications.

In embodiments, 1 to 7 tonne excavations may be used. Development of alarger models that fits on larger excavators of say 20 tons+ arepossible—they make an suitable prime mover having the weight, hydraulicflow, power, capability of variable traction control enabling the easyconversion. This is considered to provide an alternative to veryexpensive single purpose self-propelled trenchers as are presentlyavailable.

Various methodologies employ fluid assist, air assist, hammer or impactassist horizontal forward motion, low frequency vibration assistvertical motion, sonic assist vertical motion, and combinations thereof.In order to accommodate the many differing ground conditions anddiffering applications size and depth of trench the machine will vary invarious models and sizes.

One definition of trenchless technology is ‘any technique, process orprocedure, including the equipment, machines and materials involved,which minimises or eliminates the need for surface excavation or reducesenvironmental damage or reduces the associated costs for undergroundwork.’

Since 2006 plowing technology (cable plow/mole plow technology) has beenaccepted as a trenchless technique. The embodiments described areconsidered, at least to some extent, provide a trenchless technology.

Some embodiments are considered a trenchless process or a beneficialprocess that for example sits between HDD horizontal directionaldrilling say at $45 per meter for 50 mm pipe being more expensive andploughing being more disruptive but cheaper say at $25 per meter 50 mmpipe on cost basis.

In a number of embodiments there is provided a power assisted rotatingmilling auger plow trencher and pipe and cable laying mechanism thatvibrates and injects fluids and gases while bracing itself in the trenchand jacking forward to bare massive thrust on the trench face byautomated repeat actions. Some embodiments may of course only utilizesome of the above actions.

In one test the applicant has found that rate the mechanism is at leastcapable of effectively cutting soft to medium rock up to 8000 psi or 3moh's hardness scale at 30 meters per hour.

Embodiments may include:

-   -   Hydrolic driven attachment    -   Attachment version with direct drive on board motor 150 Hp    -   Agricultural tractor drawn 400 Hp PTO drive Trailed device    -   Self-propelled on tracks    -   Excavator mounted larger diameter installations    -   Subsea ocean floor pipe and cable laying Mounted to ROV    -   Continuous laying deep concrete foundation diaphragm Piling        walls.    -   Other uses to be identified

Various embodiment use a milling auger mounted on steering rudder to cutand transport the spoil to the surface relieving a narrow channel andclearing the path for the laying keel reducing energy required to openthe formation. This process is considered to apply energy i.e. HP in arelatively effective way allowing the prime mover to be smaller lighteras some existing systems need to exert as much 200 tons of drawbar forceto break hard ground.

If compared to the only 2 common trenchers mechanisms which chaincutters or rock wheels the systems have many benefits, it is efficientand compact. The configurations vary to match application and variety ofground condition form rock to below water table.

There are a number of distinct potential build configurations. Theconfigurations may utilize various forms of enhancement such as high andlow frequency vibration liquid and air injection.

Existing products includes: Excavators 1 . . . 7 ton; Excavators 7 . . .20 ton; Excavators 20 . . . 35 ton; Large Rock wheel Tesmech 1100;Agricultural Drainage Plow Bron; Agricultural Drainage Plow attachmentGold digger; Static Dozer Plows CAT D8; Plow attachments Bron; VibratoryPlow Vermeer Renegade; Small Vibe plow Vermeer 120t Small Rock wheelCase 960; Small Chain Trencher Ditchwitch RT115; Large Chain trencherMastenbrock; Spider Plow Fokersperge; Caditcha D9 Telstra; Sub Sea ROVMounted SubSea; Eco trencher USA.

We perceive a mass market in the subsequent range of designs that willencompass various plants capabilities. For example development of alarger models that fit on larger excavators of say 20 tons+. They areenvisaged to make a prime mover having the weight, hydraulic flow,power, capability of variable traction control enabling easy conversion.There are a number of such larger excavators throughout the world andthey are comparatively cheap. This would be an alternative to veryexpensive single purpose self-propelled trenchers.

Configuration Variables: Size and Prime mover it fitted to suitapplication; 5× Auger/Miller configuration to suit ground conditions; 5×Energy assist methodologies that suit the system all causing some formof liquefaction (Fluid assist; Air assist; 3 Hammer or impact assistHorizontal Forward motion; 4. Low frequency vibration assist VerticalMotion; Sonic assist Vertical Motion). Or any combination of one or moreof the above methodologies.

In order to allow for any one of the many differing ground conditionsand differing applications size and depth of trench the machine will bein various models and sizes multi-purpose as possible buy configurationof the implement. A family of machines will have different capabilitiesand attributes.

Rock capabilities are generally specified in the following ranges: softrock (0-6 kpsi), medium rock (7-12 kpsi), medium hard rock (13-25 kpsi)and hard rock (26 to 45 kpsi)

Initial trails have concluded that the prototype mechanism is capable ofeffective cutting soft to medium rock up to 8000 psi or 3 moh's hardnessscale at (the cutting being at a production 30 meters per hour). Thesteerable keel keeps the machine traveling straight with steering due tothe sideways pulling effect of rotational action of the milling auger

One of the advantages is that embodiments can be provided as anattachment that means machine expenditure is relatively low compared tosingle purpose specialist trenchers. In embodiments there is consideredto be provided a trenchless technology that sits as example between HDDhorizontal directional drilling $45 per meter for 50 mm pipe being moreexpensive and ploughing being more disruptive but cheaper $25 per meter50 mm pipe on cost basis

The extreme heavy work load environment has meant we have had todeveloped a special base support arrangement for the bottom end assemblywhich works as the rotational bearing and the quick release auger changeout system

It is to be appreciated that each of the embodiments is specificallydescribed and that the present invention is not to be construed as beinglimited to any specific feature or element of any one of theembodiments. Neither is the present invention to be construed as beinglimited to any feature of a number of the embodiments or variationsdescribed in relation to the embodiments.

It is to be recognised that various alterations and equivalent forms maybe provided without departing from the spirit and scope of the presentinvention. This includes modifications within the scope of the appendedclaims along with all modifications, alternative constructions andequivalents.

There is no intention to limit the present invention to the specificembodiments shown in the drawings. The present invention is to beconstrued beneficially to the applicant and the invention given its fullscope.

In the present specification, the presence of particular features doesnot preclude the existence of further features. The words ‘comprising’,‘including’ and ‘having’ are to be construed in an inclusive rather thanan exclusive sense.

1-41. (canceled)
 42. An excavation system comprising: a body; and anexcavation device for being moved by a vehicle to excavate material fromthe ground; and a steering system for altering the steering of theexcavation device.
 43. An excavation system as claimed in claim 42wherein the body is provided in the form of a keel-type structure. 44.An excavation system as claimed in claim 42 wherein the excavationdevice is inclined to extend towards the vehicle in the directionextending into the ground when the excavation device is being moved bythe vehicle to excavate material.
 45. An excavation system as claimed inclaim 42 wherein the inclination of the excavation device is backwardlysloping to allow a bottom support bearing housing to clear the base of atrench.
 46. An excavation system as claimed in claim 42 wherein theexcavation device comprises an auger.
 47. An excavation system asclaimed in claim 42 wherein the body is provided in the form of akeel-type structure and the keel-type structure shields the conduit,while being laid, from excavated earth.
 48. An excavation system asclaimed in claim 47 wherein the keel-type structure includes a number ofprojections that extend along the keel-type structure to restrain soilfrom falling into the bottom of the trench.
 49. An excavation system asclaimed in claim 42 having an auto pilot system to extend the cuttingdevice and sweep left and right.
 50. An excavation system as claimed inclaim 42 wherein the steering system includes a mount having adirectional joint for allowing the excavation device to be directed leftor right when being moved by the vehicle.
 51. An excavation system asclaimed in claim 50 including at least one hydraulic piston arrangedeither side of the directional joint for steering the excavation device.52. An excavation system as claimed in claim 42 wherein the steeringsystem is used to counteract a rotation effect of the excavation device.53. An excavation system as claimed in claim 42 wherein the steeringsystem allows for a swing action to be engaged in an automaticcontinuous swing mode.
 54. An excavation system as claimed in claim 42wherein the steering system includes a deflector for varying the forceapplied by the ground to the excavation system to control the degree towhich the excavation device turns.
 55. An excavation system as claimedin claim 42 wherein the steering system comprises two moveable surfacesarranged either side of the body for using friction to control thedegree to which the excavation device turns.
 56. An excavation system asclaimed in claim 42 including a locking system for selectively assistingwith preventing the excavation device from moving backwards.
 57. Anexcavation system as claimed in claim 56 wherein the locking systemcomprises a wedge arrangement fir bearing against the side walls of atrench formed by the excavation system.
 58. An excavation system asclaimed in claim 57 wherein the wedge arrangement comprises at least onemovable abutment the or each for bearing against a corresponding sidewall of a trench formed by the excavation system.
 59. An excavationsystem as claimed in claim 42 wherein the body is provided forconnection to the vehicle; the excavation device being connected to thebody so as to be disposed forwardly of the vehicle when being moved bythe vehicle to excavate material.
 60. An excavation system as claimed inclaim 42 including a length laying guide arrangement, the length layingguide arrangement being disposed between the excavation device and thevehicle, when the excavation device is being moved by the vehicle toexcavate material, the length laying guide arrangement including aninlet guide arrangement and an outlet guide arrangement, the inlet guidearrangement being adapted to receive a feed of conduit or cable fromabove in a position between the excavation device and the vehicle; andthe outlet guide arrangement being adapted to provide the conduit orcable in a substantially horizontally extending position.
 61. Anexcavation system as claimed in claim 60 wherein the excavation deviceis inclined by between 20 to 30 degrees away from vertical.
 62. Anexcavation system having an inwardly projecting excavation device and alength laying guide arrangement, the excavation device being disposedforwardly of a length laying guide arrangement to allow the excavationdevice to be driven forwardly and for conduit or cable to be laidtherebehind.
 63. An excavation system as claimed in claim 62 whereinexcavation device is spaced at least one meter away from the mountarrangement.
 64. An excavation system as claimed in claim 62 wherein thelength laying guide arrangement includes a guide adapted to flex theconduit by about 45 degrees or less.
 65. A method for laying lengths ina trench comprising: positioning an excavation device in front of lengthlaying guide and a vehicle; driving the excavation device in a forwarddirection using the vehicle and laying lengths using the length layingguide, the length laying guide being disposed between the excavationdevice and the vehicle.
 66. A method as claimed in claim 65 includingautomatically moving the excavation device left and right to counteracta rotation effect of the excavation device